In order to provide semiconductor devices with a more rapid operational speed and increased integration degree, a channel length of a MOS field effect transistor (MOSFET) has been gradually reduced. However, this may cause a short channel effect.
Therefore, a fin-type field effect transistor (FinFET) having a three dimensional channel region may be of increasing interest in the semiconductor business because it may reduce the short channel effect and may increase drive current of the MOSFET at a low operation voltage.
Some research has been conducted on the use of an epitaxial layer having a tensile or compressive stress in the semiconductor devices to increase carrier mobility in a channel region of the MOSFET.